Phosphoro derivatives of alpha-(methylthio) cresols



United States Patent 3,337,653 PHOSPHORO DERIVATIVES 0F DL'UVIETHYL- THIO) CRESOLS Karoly Szabo, Orinda, Calif., and John Gary Brady, West Chester, Pa, assignors to Staulfer Chemical Company,

New York, N.Y., a corporation of Delaware No Drawing. Filed Apr. 15, 1964, Ser. No. 360,061

6 Claims. (Cl. 260-948) This invention relates to certain novel chemical compounds and to the use of such compounds as insecticides, acaricides and the like. More specifically, this invention relates to phosphoro derivatives of a-(methylthio) cresols corresponding to compounds of the formula CHzSCH;

R1 X1 wherein R is selected from the group consisting of lower alkyl, lower alkoxy and phenyl, R is lower alkoxy, X is selected from the group consisting of sulfur and oxygen, and X is selected from the group consisting of halogen, nitro and lower alkyl radicals.

The compounds of the present invention can be prepared by contacting a substituted phenolic sulfide with an appropriate phosphorylating agent in the presence of an inorganic base, such as potassium hydroxide, or a tertiary N- base such as pyridine, triethylamine and the like. Examples of said phosphorylating agents are the 0,0- disubstituted phosphorochloridates, 0,0 disubstituted phosphoro-chloridothioates, substituted phosphono-chloridates and substituted phosphonochloridothioates. The preparation of compounds of a phenolic character which may be used as starting materials is described by Long and Moss in U.S. Patent 2,976,325.

The compounds of the present invention can be made as further illustrated in the following examples: Compound numbers have been assigned to each compound according to the example number in which it is prepared and are used hereinafter for convenience.

EXAMPLE 1 O-ethyl-O-[a -(methylthio)-2,4-xylyl]- ethylphosphonothioate Equal molar portions (0.04 M) of m -(methylthio)- 2,4-xylenol, and O-ethyl-ethylphosphonochloridothioate were allowed to react in methylethyl ketone with 4.3 g. of triethylamine present. The mixture was refluxed for 8 hours at 83 C. The amine hydrochloride formed was filtered out. The filtrate was washed with 1% sodium hydroxide solution (100 m1.) and water (50 ml.) subsequently. The organic layer was separated and dried over anhydrous magnesium sulfate and filtered. The organic solvent was removed by heating to 140 C. at 0.5 mm. pressure. The product obtained analyzed correctly for sulfur and phosphorous values according to the assigned structure and had a refractive index of 1.5457.

EXAMPLE 2 O-ethyl-O- [2-chl0ro-amethylthio -p-t0lyl] ethy lphosphonothioate In the same manner as Example 1, 2-chloro-a-(methylthio)-p-cresol was allowed to react with O-ethyl-ethylphosphonochloridothioate. The product obtained was a pale yellow oil with a refractive index of 1.5617 at 24 C.

EXAMPLE 3 0,0-dr'ethyl-O-[Z-chloro-a-(methylthio) -p-t0lyl]- phosphorothioate In the same manner as Example 1, 2-chIoro-a-(methyl- 3,337,653 Patented Aug. 22, 1967 thio-p-cresol was allowed to react with 0,0-diethylphosphorochloridothioate. The product obtained was a light brown oil with a refractive index of 1.5490 at 25 C.

EXAMPLE 4 0,0-dimethyl-O- [2-chl0r0-ot-(methylthio)-p-tolyl]- phosphorot'hioate EXAMPLE 5 O-n-propyl-O-[2-chl0r0-a-(methylthio)-p-tolyl]- ethylphosphonothioate.

In the same manner as Example 1, 2-chloro-a-(methylthio)-p-cresol was allowed to react with O-n-propylethylphosphonochloridothioate. The product was a pale yellow oil with a refractive index of 1.5522 at 25 C.

EXAMPLE 6 O-methyl-O-[Z-chloro-a-(methylthio)-p-tolyl]- ethylphosphonothioate In the same manner as Example 1, 2-chloro-a-(methylthio)-p-cresol was allowed to react with O-methylethylphosphonochloridothioate. The product was obtained in a yield of 97 percent and had a refractive index of 1.5622 at 25 C.

EXAMPLE 7 O-ethyl-O- [2-chl0r0-a- (methylthio) -p-t0ly] phenylphosphanothioate In the same manner as Example 1, 2-chloro-u-(methylthio-p-cresol was allowed to react with O-ethylphenylphosphonochloridothioate. The product was obtained in a quantitative yield. It had a refractive index of 1.5877 at EXAMPLE 8 O-ethy l-O- [2-chl0r0-a- (methylthilo) -p-toly chloromethy lphosphonothioate In the same manner as Example 1, 2-chloro-oc-(methylthio)-p-cresol was allowed to react with O-ethyl-chloromethylphosphonochlororidothioate. The product was obtained in a yield of 82%, refractive index 1.5754 at 25 C.

EXAMPLE 9 In the same manner as Example 1, 2,4-dichloro-a- (methylthio)-o-cresol was allowed to react with 0,0-diethyl-phosphorochloridothioate. The product was obtained in a yield of 79%, refractive index 1.5587 at 25 C.

EXAMPLE 10 O-ethyl-O- [4,6-dich loro-nt- (methy lthio) -0-tolyl] ethy lphosph o rothioa te In the same manner as Example 1, 2,4-dichloro-a- (methylthio)-o-creso1 was allowed to react with O-ethylethylphosphonochloridothioate to give a yield of with a refractive index of 1.5653 at 25 C EXAMPLE 11 In the same manner as Example 1, 2-chloro-a-(methylthio)-p-cresol was allowed to react with diethylphos- *phorochloridate. The product was obtained in a yield of O-ethyl-O- [Z-nitrom-(methylthio) -p-tlyl] -methyl phosphonate In the same manner as Example 1, 2-nitro-a-(methylthio)-p-cresol was allowed to react with O-ethyl-methylphosphonochloridate to give a 78% yield of the title compound.

The compounds were tested as insecticides according to the following method:

Insecticidal evaluation test-Eight of the compounds were tested as insecticides against houseflies (HF), Musca domestica (Linn.). Test insects are caged in cardboard mailing tubes 3 /3 in diameter and 2%" tall. Twentyfive female flies, three to five days old, are caged in the tubes. The tubes are supplied with cellophane bottoms and coarse mesh nylon tops. The candidate toxicant is dissolved in a volatile solvent, preferably acetone. The active compound is pipetted into a Petri dish bottom, allowed to air dry and placed in the mailing tube cages. The flies are continuously exposed to the known residue of the active compound in the cage. After twenty-four and forty-eight hours, counts are made to determine living and dead insects. The LD50 values are calculated using well known procedures.

Various changes and modifications may be made without departing from the spirit and scope of the invention described herein as will be apparent to those skilled in the art to which it pertains. It is accordingly intended that the present invention shall only be limited by the scope of the appended claims.

We claim:

1. A compound of the formula CH2SCH3 wherein R is selected from the group consisting of lower alkyl, lower alkoxy and phenyl radicals, R is lower alkoxy, X is selected from the group consisting of sulfur and oxygen and X is selected from the group consisting of chlorine, nitro and lower alkyl radicals.

2. The compound O-ethyl-O-[2-chloro-zx-(methylthio)- p-tolyl] -ethylph osphonothioate.

3. The compound 0,0-diethyl-O-[2-chloro-a-(rnethylthio -p-tolyl] -phosphorothioate.

4. The compound O-ethyl-O-[2-nitro-a-(methylthio)- p-tolyl]-methylphosphonate.

5. The compound O-ethyl-O-[4,6-dichloro-u-(methylthio) -O-tolyl] -ethylphosphonothioate.

6. The compound O-ethyl-O-[2-chloro-a-(methylthio)- p-tolyl] -phenylphosphonothioate.

Insect Specie Compound Code (LD values g.)

HF 10 130 30 30 30 100 30 i 30 100 75 The compounds of this invention were also found to References Cited control American cockroach, Periplaneta americana UNITED STATES PATENTS (Linn.), large milkweed bug, Oncopeltus fasciatus (Dal- 45 I las) and two-spotted mites, Tetranychus telarius (Linn.). 2611729 9/1952 Bartlett et n 2,793,224 5/1957 Fancher 260-461 Compound number .2 was found to be particularly effec- 2 995 487 8/1961 Jones et a1 167 30 tive in the control of pea aphid. The percent concentra- 3O54756 9/1962 i trigig 112 X lgglogliltable for pea aphid COl'ltIOl Value) WaS 50 h p X 3,089,893 5/1963 Dever et al. 260461 The compounds of the present invention may be applied to a pest habitat in ways well known to those skilled in the art, such as dusts, sprays of solutions or dispersions and the like,

CHARLES B. PARKER, Primary Examiner. J. S. LEVITT, Examiner. G. A MENTIS, A. SU'I'IO, Assisianl Examiners. 

1. A COMPOUND OF THE FORMULA 